diff options
| author | Johan Hovold <jhovold@gmail.com> | 2013-10-16 11:56:14 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-04 10:55:46 -0800 |
| commit | 54f830b7337ed016b6708cf5a2ac297d4cee227d (patch) | |
| tree | 09ecfb244483aa3961c21d840232336c87db765c /arch/arm/mach-at91/at91sam9n12.c | |
| parent | 208a11c4412dee65ccf76503fb980d7fb3c5c743 (diff) | |
ARM: at91: fix hanged boot due to early rtc-interrupt
commit 6de714c21a8ea315fffba6a93bbe537f4c1bf4f0 upstream.
Make sure the RTC-interrupts are masked at boot by adding a new helper
function to be used at SOC-init.
This fixes hanged boot on all AT91 SOCs with an RTC (but RM9200), for
example, after a reset during an RTC-update or if an RTC-alarm goes off
after shutdown (e.g. when using RTC wakeup).
The RTC and RTT-peripherals are powered by backup power (VDDBU) (on all
AT91 SOCs but RM9200) and are not reset on wake-up, user, watchdog or
software reset. This means that their interrupts may be enabled during
early boot if, for example, they where not disabled during a previous
shutdown (e.g. due to a buggy driver or a non-clean shutdown such as a
user reset). Furthermore, an RTC or RTT-alarm may also be active.
The RTC and RTT-interrupts use the shared system-interrupt line, which
is also used by the PIT, and if an interrupt occurs before a handler
(e.g. RTC-driver) has been installed this leads to the system interrupt
being disabled and prevents the system from booting.
Note that when boot hangs due to an early RTC or RTT-interrupt, the only
way to get the system to start again is to remove the backup power (e.g.
battery) or to disable the interrupt manually from the bootloader. In
particular, a user reset is not sufficient.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/mach-at91/at91sam9n12.c')
| -rw-r--r-- | arch/arm/mach-at91/at91sam9n12.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/at91sam9n12.c b/arch/arm/mach-at91/at91sam9n12.c index c7d670d1180..4d6001c355f 100644 --- a/arch/arm/mach-at91/at91sam9n12.c +++ b/arch/arm/mach-at91/at91sam9n12.c @@ -223,7 +223,13 @@ static void __init at91sam9n12_map_io(void) at91_init_sram(0, AT91SAM9N12_SRAM_BASE, AT91SAM9N12_SRAM_SIZE); } +static void __init at91sam9n12_initialize(void) +{ + at91_sysirq_mask_rtc(AT91SAM9N12_BASE_RTC); +} + AT91_SOC_START(at91sam9n12) .map_io = at91sam9n12_map_io, .register_clocks = at91sam9n12_register_clocks, + .init = at91sam9n12_initialize, AT91_SOC_END |